Recep Ekin Kubilay^1*, Alireza Ghafarollahi^1*, Francesco Maresca^2*, W.A. Curtin^1*

1 Laboratory for Multiscale Mechanics Modeling, Institute of Mechanical Engineering, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland

2 Engineering and Technology Institute Groningen, Faculty of Science and Engineering, University of Groningen, 9747 AG Groningen, The Netherlands

* Corresponding authors emails: recep.kubilay@epfl.ch, alireza.ghafarollahi@epfl.ch, f.maresca@rug.nl, william.curtin@epfl.ch

DOI10.24435/materialscloud:2y-yn [version v1]

Publication date: Oct 29, 2021

How to cite this record

Recep Ekin Kubilay, Alireza Ghafarollahi, Francesco Maresca, W.A. Curtin, High energy barriers for edge dislocation motion in body-centered cubic high entropy alloys, Materials Cloud Archive 2021.183 (2021), doi: 10.24435/materialscloud:2y-yn.

Description

Recent theory proposes that edge dislocations in random body-centered cubic (BCC) high entropy alloys have high barriers for motion, conveying high strengths up to high temperatures. Here, the energy barriers for edge motion are computed for two model alloys, NbTaV and MoNbTaW as represented by interatomic potentials, using the Nudged Elastic Band method and compared to theoretical predictions. The average magnitude of the barriers and the average spacing of the barriers along the glide direction agree well with the analytical theory, with no adjustable parameters. The evolution of the barriers versus applied stress is modeled, and the mean strength is in reasonable agreement with the predicted zero-temperature strength. These findings validate the analytic theory. A reduced analytic model based on solute misfit volumes is then applied to Hf-Mo-Nb-Ta-Ti-Zr and Mo-Nb-Ta-Ti-V-W alloys, rationalizing the observed significant strength increases at room temperature and 1000 ∘C upon addition of solutes with large misfit into a base alloy. The analytic theory for edge motion is thus a powerful validated tool for guiding alloy selection.

Materials Cloud sections using this data

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File name	Size	Description
Kubilay_bcc.tar.gz MD5md5:2583f2689d35e3bcfdd59ed19324df8c	353.0 MiB	Scripts and data used in the publication with a README file with folder descriptions
README.txt MD5md5:80396914cf89b6c03fd320803ca8de50	708 Bytes	README file

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External references

Keywords

High Entropy Alloys Solute Strengthening Atomistic Models SNSF